The Phoenix Road bridge in northern Baltimore County will close to vehicle traffic for an unspecified period for emergency repair work, according to the Baltimore City Department of Transportation.

The bridge, which crosses Gunpowder Falls and the NCR Trail east of York Road, will close between York and Carroll roads at 6 a.m. Friday until new traffic control devices have been installed as part of a realignment of the traffic pattern. Detours will be in effect.

While the bridge is located in the county, it is owned by the city, which owns the reservoirs in the vicinity and operates the regional water system. The city said it will maintain access for local residents.

If you go to google maps and type in the following address which is at the corner of Dulaney Valley and Loch Raven Dr. there is a little stream just east of that. That is the bridge I think Steve is talking about.
12460 Dulaney Valley Road, Lutherville-Timonium, MD